• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.9
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• pp.741-746
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• 2009

Compare to conventional Indium Tin Oxide (ITO) film deposition methods, cesium assisted sputtering method has been shown superior electrical, mechanical, and optical film properties. However, it is not easy to use cesium assisted sputtering method since ITO film properties are very sensitive to Cesium assisted equipment condition but their mechanism is not yet clearly defined physically or mathematically. Therefore, to optimize deposited ITO film characteristics, development of accurate and reliable process model is essential. For this, in this work, we developed ITO film deposition process model using neural networks and design of experiment (DOE). Developed model prediction results are compared with conventional statistical regression model and developed neural process model has been shown superior prediction results on modeling of ITO film thickness, sheet resistance, and transmittance characteristics.

• Journal of the Korean Vacuum Society
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• v.18 no.1
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• pp.30-36
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• 2009

The effects of $HfO_2$ film thickness on electrical, optical, and structural properties were investigated. We fabricated ITO/$HfO_2$/ITO metal-insulator- metal (MIM) capacitor using transparent conducting oxide. When $HfO_2$ film thickness increase from 50 nm to 300 nm, dielectric constant of $HfO_2$ was decreased from 20.87 to 9.72. The transparent capacitor shows an overall high performance, such as a dielectric constant about 21 by measuring the ITO/$HfO_2$/ITO capacitor structures and a low leakage current of $2.75{\times}10^{-12}\;A/cm^2$ at +5 V. Transmittance above 80% was observed in visible region.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.2
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• pp.352-356
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• 2011

Transparent conducting oxide films like ITO/Au/ITO and AZO/Au/AZO were fabricated with a sputter at a low-temperature of less then $70^{\circ}C$ and their crystallization and opto-electrical properties were studied. X-ray diffractiometry showed that single-ITO layer was amorphous, whereas, ITO of ITO/Au/ITO multi-layer was crystal. The ITO crystallization and its orientation depended on Au crystallization. Surface roughness of the ITO-multi-layers were in the range of 29-88% of that of ITO-single layer. ITO on amorphous gold layer had more rough surface than ITO on crystal gold. The gold layer between ITO improved electrical conductivity. Carrier density, mobility, resistivity and sheet resistance of ITO-single layer were $2.3{\times}10^{19}/cm^3$, $85{\times}cm^2$/Vs, $31{\times}10^{-4}{\Omega}cm$, and $310{\times}{\Omega}/cm^2$, respectively. Those of ITO/Au/ITO-multi-layers depended on Au-interlayer-thickness, which were in the range of $3.6{\times}10^{19}{\sim}4.2{\times}10^{21}/cm^3$, $43{\sim}85cm^2$/Vs, $0.17{\times}10^{-4}{\sim}25{\times}10^{-4}{\Omega}cm$, and $1.7{\sim}20{\times}{\Omega}/cm^2$, respectively. The sheet resistances of the single-layer ITO and the multi-layer ITO were 310 and $2.7{\sim}21{\Omega}/cm^2$, respectively. That of AZO/Au/AZO was $8.6{\Omega}/cm^2$, which was better than the single-layer ITO.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.276-276
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• 2008

Transparent and conducting indium tin oxide (ITO) and ITO/Nickel/ITO(INI) multilayered films were prepared on glass substrates by a magnetron sputtering without intentional substrate heating. The RF(13.56MHz) and DC power were applied to ITO and Nickel target, respectively. The thickness of ITO, Ni and ITO films were kept constantly at 50, 5 and 45 nm. In order to consider the effect of post deposition vacuum annealing in vacuum on the physical and optoeletrical properties of INI films, optical transmittance, electrical resistivity, crystallinity of the films were analyzed. From the observed result, it may conclude that the optoelectrical properties of the INI films were dependent on the post deposition annealing. For the INI films annealed at $300^{\circ}C$, the films have a polycrystalline structure with (110), (200), (210), (211) and (300). The resistivity of the films were $4.0\times10^{-4}{\Omega}cm$ at room temperature. As the annealing($300^{\circ}C$), resistivity decreased to $2.8\times10^{-4}{\Omega}cm$. And also the optical transmittance decreased from 79 to 70 % at 550nm.

• Journal of the Korean Society for Heat Treatment
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• v.23 no.5
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• pp.245-248
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• 2010

Sn doped $In_2O_3$ (ITO) and ITO/Ni/ITO (INI) multilayer films were deposited on the glass substrates with a reactive magnetron sputtering system without intentional substrate heating and then the influence of the Ni interlayer on the methanol gas sensitivity of ITO and INI film sensors were investigated. Although both ITO and INI film sensors have the same thickness of 100 nm, INI sensors have a sandwich structure of ITO 50 nm/Ni 5 nm/ITO 45 nm. The changes in the gas sensitivity of the film sensors caused by methanol gas ranging from 100 to 1000 ppm were measured. It is observed that the INI film sensors show the higher sensitivity than that of the ITO single layer sensors. Finally, it can be concluded that the INI film sensor have the potential to be used as improved methanol gas sensors.

• Transactions on Electrical and Electronic Materials
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• v.7 no.5
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• pp.267-270
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• 2006

The Indium tin oxide (ITO) films were deposited on CR39 substrate using DC magnetron sputtering. ITO thin films deposited at room temperature because CR39 substrates its glass-transition temperature of is $130^{\circ}C$. ITO thin films used bottom and top electrode and for organic thin film transparent transistor.(OTFT) ITO thin film electrodes electrical properties and optical transparency properties in the visible wavelength range (300 - 800 nm) strongly dependent on volume of oxygen percent. For the optimum resistivity and transparency of ITO thin film electrode achieved with a 75 W plasma power, 10 % volume of oxygen and a 27 nm/min deposition rate. Above 85 % transparency in the visible wavelength range (300 - 800 nm) measured without post annealing process and $9.83{times}10{-4}{\Omega}cm$ a low resistivity was measured thickness of 300 nm.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2006.10a
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• pp.56-59
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• 2006

The ITO thin films were prepared by FTS (Facing Targets Sputtering) system on polycarbonate (PC) substrate. The ITO thin films were deposited with a film thickness of 100nm at room temperature. As a function of sputtering conditions, electrical and optical properties of prepared ITO thin films were measured. The electrical and optical characteristics of the ITO thin films were evaluated by Hall Effect Measurement (EGK) and UV-VIS spectrometer (HP), respectively. From the results, the ITO thin film was deposited with a resistivity $8{\times}10^{-4}[{\Omega}-cm]$ and transmittance over 80%.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.12
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• pp.1277-1282
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• 2004

ITO films on PET substrate were prepared by DC magnetron sputtering method using powdery target with different deposition conditions. In addition, the electrical and optical properties were investigated. As the sputtering power and working pressure were higher, the resistvity of ITO films increased. The optical transmittance deteriorated with increasing sputtering power and thickness. As the working pressure increased, however, the optical transmittance improved at visible region of light. From these results, we could deposited ITO films with 8${\times}$10$^{-3}$ $\Omega$-cm of resistivity and 80 % of transmittance at optimal conditions.

• Korean Journal of Materials Research
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• v.17 no.4
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• pp.232-235
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• 2007

Indium tin oxide (ITO) films were deposited on polycarbonate CR39 substrate using DC magnetron sputtering. ITO thin films were deposited at room temperature because glass-transition temperature of CR39 substrate is $130^{circ}C$ ITO thin films are used as bottom and top electrodes and for organic thin film transparent transistor (OTFT). The electrodes electrical properties of ITO thin films and their optical transparency properties in the visible wavelength range (300-800 nm) strongly depend on the volume of oxygen percent. The optimum resistivity and transparency of ITO thin film electrode was achieved with a 75 W plasma power, 10 % volume of oxygen and a 27 nm/min deposition rate. Above 85% transparency in the visible wavelength range (300-800 nm) was measured without post annealing process, and resistivity as low as $9.83{\times}^{TM}10^{-4}{\Omega}$ cm was measured at thickness of 300 nm.

• Proceedings of the KIEE Conference
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• 2006.10a
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• pp.69-70
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• 2006

The ITO thin films were prepared by Facing Targets Sputtering(FTS) method on polyethersulfon(PES) substrate. The ITO thin films were deposited with the film thickness of 100nm at room temperature and working gas pressure of 1 mTorr. As a function of sputtering conditions, electrical and optical properties of prepared ITO thin films were evaluated by Hall Effect Measurement(EGK) and UV-VIS spectrometer(HP), respectively. From the results, the ITO thin films was deposited was with a resistivity $8.3{\times}10^{-4}[{\Omega}-cm]$ and transmittance over 80% in the visible range.